Why the government is investing so much in airline security while leaving trains vulnerable

Anyone who has boarded an Amtrak train since Sept. 11, 2001, must wonder how long the delusion can last. How easy it is to waltz into a teeming station 10 minutes before departure, pull your ticket from a machine and glide onto the train without any inspection of your ID or your bags. Your shoes are of no interest to anyone. It's as if Amtrak has been exempted from modernity, and all the fuzzy charm of taking the train remains untouched by time.

The tragedy in Madrid may have put an end to the railroad anachronism. The attack that killed...